fix: Remove phone_number_id param from WhatsApp media retrieval for incoming messages (#13319)

Fixes https://github.com/chatwoot/chatwoot/issues/13317
Fixes an issue where WhatsApp attachment messages (images, audio, video,
documents) were failing to download. Messages were being created but
without attachments.

The `phone_number_id` parameter was being passed to the `GET
/<MEDIA_ID>` endpoint when downloading incoming media. According to
Meta's documentation:

> "Note that `phone_number_id` is optional. If included, the request
will only be processed if the business phone number ID included in the
query matches the ID of the business
  phone number **that the media was uploaded on**."

For incoming messages, media is uploaded by the customer, not by the
business phone number. Passing the business's `phone_number_id` causes
validation to fail with error: `Param phone_number_id is not a valid
whatsapp business phone number id ID`

This PR removes the `phone_number_id` parameter from the media URL
request for incoming messages.

spec/services/whatsapp/incoming_message_whatsapp_cloud_service_spec.rb

@@ -41,10 +41,7 @@ describe Whatsapp::IncomingMessageWhatsappCloudService do
       it 'increments reauthorization count if fetching attachment fails' do
         stub_request(
           :get,
-          whatsapp_channel.media_url(
-            'b1c68f38-8734-4ad3-b4a1-ef0c10d683',
-            whatsapp_channel.provider_config['phone_number_id']
-          )
+          whatsapp_channel.media_url('b1c68f38-8734-4ad3-b4a1-ef0c10d683')
         ).to_return(
           status: 401
         )
@@ -112,10 +109,7 @@ describe Whatsapp::IncomingMessageWhatsappCloudService do
   def stub_media_url_request
     stub_request(
       :get,
-      whatsapp_channel.media_url(
-        'b1c68f38-8734-4ad3-b4a1-ef0c10d683',
-        whatsapp_channel.provider_config['phone_number_id']
-      )
+      whatsapp_channel.media_url('b1c68f38-8734-4ad3-b4a1-ef0c10d683')
     ).to_return(
       status: 200,
       body: {